Method and compositions for preserving wine

ABSTRACT

Resveratrol and/or pterostilbene are added to wines to preserve the wine from oxidation, bacteria and fungi, as well as to deliver resveratrol to an animal. The resveratrol and/or pterostilbene are also added to red wine to preserve the polyphenols present in red wine. The resveratrol and/or pterostilbene can be added to grape must prior to fermentation and/or to fermented wine prior to bottling.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation-in-part of application Ser. No. 12/350,332, filedJan. 8, 2009 now abandoned, which claims priority from provisionalapplication Ser. No. 61/019,745, filed Jan. 8, 2008, the entire contentsof each of which are hereby incorporated by reference.

FIELD OF THE INVENTION

The present application relates to a method and compositions forpreserving wine and as well as preserving the antioxidant polyphenolsthat are present in red in wine.

BACKGROUND OF THE INVENTION

Wine is traditionally defined as an alcoholic beverage produced whenfruit undergoes primary fermentation in which yeast converts the sugarin fruit to alcohol. When the sugar supply is exhausted, the yeast diesoff, leaving the alcohol produced to blend with, or attach to, othercomponents.

Almost all wine improves with aging. However, peak flavor and bouquetmay require years to develop in wines with high concentrations oftannins, and many wines deteriorate not long after reaching their peak.Chemical reactions during the aging process are extremely complex andwell documented. The desirable characteristics of wine result from ablending of the components in the wine.

Wines without high concentrations of tannins develop flavor and bouquetmore rapidly. These wines may also deteriorate not long after reachingtheir peak.

The traditional wine aging process is simple, well known, and wellunderstood. Oxidation is among the greatest problems with which awinemaker deals during the making and aging process for wine. Oxidationcan adversely affect the fruity flavor and freshness of wine. In orderto prevent oxidation of the wine, sulfur dioxide (as potassiummetabisulfite or sodium metabisulfite) is frequently added to grape mustbefore fermentation to inhibit or kill all unwanted bacteria prior tothe point at which the alcohol production commences after fermentationbegins. The metabisulfite salts are converted to sulfur dioxide, whichis the so-called “free sulfite” of wine. After fermentation producessome alcohol, the sterilizing effects of alcohol assist in killing theunwanted bacteria.

In some wines, particularly those of the Sauternes type, a considerablequantity of naturally-occurring sulfur dioxide is retained in the wineuntil the wine is bottled. In red wines and in some white wines, sulfurdioxide is added to prevent the wine from becoming unsound.

When sulfur dioxide is first added in the free state, it rapidlycombines with other substances in the wine, so that sometimes in a fewminutes, and, in other cases, in as much as thirty minutes, the amountof free sulfur dioxide is halved. Over a period of weeks or months, theexact rate of disappearance depends upon many factors, such astemperature and amount of aeration, whereby the total sulfur dioxidecontent of the wine falls.

During the normal aging process for wine, the conditioners andpreservatives, such as sulfur dioxide, are dispersed throughout theliquid. Changes in the wine following bottling are subtle and difficultto establish, since there are no measurements other than taste and smellthat are used to determine when the aging process is complete and whenthe wine invariably begins its decline. Further, the ingredients usedvary among wines and winemakers, and each ingredient may affect theaging process differently.

There is a direct relation between the amount of sulfite added and theinhibition of bacterial growth in wine. As such, large scale wineproducers, whose risks are high, may use a relatively high concentrationof additives such as sulfite to avoid spoilage. However, with theaddition of large amounts of sulfites, the wine can be adverselyaffected, irrespective of the lack of bacterial deterioration.

Some smaller wine producers advertise that they do not use sulfite. Thisis important to many consumers, as some consumers complain of headacheswhich are attributed to the presence of sulfite in wines, even thoughall wines contain a small amount of naturally occurring sulfites.Although the relationship between sulfites in wine and headaches has notbeen clinically confirmed, many believe that the link is real. As such,wines not containing added sulfites may command a higher retail price,because manufacturing costs are higher and the risk of losing entirebatches of wine to bacterial contamination and/or oxidation is borne bythe consumer.

Although all wines naturally contain some sulfites as a result of thefermentation process, the amounts of these sulfites are not noticeableto most people. However, when sulfites are added to the must, duringfermentation and more so after bottling, gaseous hydrogen sulfidedevelops in the wine. This gas is extremely toxic and, in many cases,may destroy what would otherwise be a good wine. The concept ofdecanting the wine, or letting the wine “breathe”, in essence allows thehydrogen sulfide to volatilize out of the wine so that it is thensuitable for drinking. There is no nutritional value to the sulfitesadded to wine, and, in the case of sodium metabisulfite, consumers maywish to avoid additional sodium as well.

Red wine contains a number of antioxidant polyphenols, which scavengefree radicals and up-regulate certain metal chelation reactions. Thepolyphenols can reduce inflammatory effects such as coronary arterydisease and can inhibit the growth or occurrence of mammalian tumors.

Consuming dietary polyophenols may be associated with beneficial effectsin higher animal species, including reduction in inflammatory effectssuch as coronary artery disease, including improved endothelial healthvia down-regulation of oxidative LDL and anti-aging consequences such asslowing the process of skin wrinkling.

A high intake of polyphenols is likely to have beneficial effects on thecardiovascular system. Red wine is a rich source of polyphenols, and ithas been demonstrated that trans-resveratrol,3,4′,5-trihydroxy-trans-stilbene, has been found to be the mostefficacious stimulator of eNOS expression, which enzyme is protective ofthe cardiovascular system. However, the presence of resveratrol alonecould not explain the total stimulatory effect of red wine. Theflavanols catechin and epicatechin, the flavanols fisetin, myricetin,isoquercetin and hyperoside, the anthocyanins delphinidin, malvidin andpaeodnidin, gallic acid, and the hydroxycinnamic acids ferulic acid andsinapinic acid did not change eNOS expression or eNOS promoter activityin any substantial way. The anthocyanin cyanidin, the hydroxycinnamicacids p-coumaric acid and caffeic acid, and the phenolic acids benzoicacid and vanillic acid also enhanced eNOS expression moderately. Thus,the increase in eNOS in response to ingestion of red wine involvesseveral polyphenolic compounds, with trans-resveratrol making a majorcontribution, and lesser contributions from cinnamic and hydrocinnamicacids, cyaniding and some phenolic acids. [Nitric Oxide, 2005,12(2):97-104]

Sulfur dioxide has been shown to interact with polyphenols and oxygen inwine, which reaction is catalyzed by the presence of copper and iron,which are naturally found in wine grapes Danielewicz, Am. J. Enol.Vitic. 58(1): 53-60 2007.

SUMMARY OF THE INVENTION

It has now been discovered that resveratrol; pterostilbene, a naturalmethoxylated analogue of resveratrol; or a combination of the twocompounds, can be used as an antioxidant, fungicide and bactericide inwine. Resveratrol and pterostilbene have no known side effects inhumans, and can be used as a replacement for sulfites that areconventionally added to wines as preservatives.

In addition, the resveratrol, pterostilbene or a combination thereof arealso used to preserve the antioxidant polyphenols in red wine.

The resveratrol, pterostilbene, or combination thereof, can be added tothe grape must prior to fermentation, during fermentation, and at thetime of bottling the wine. Since the yeast during fermentation and thealcohol produced during fermentation do not adversely affect thepterostilbene or resveratrol, the time of addition of these compounds isnot critical.

Grapes, and some other fruits and vegetables such as Vaccinium berries,normally produce resveratrol as a defense mechanism when being attackedby some extraneous fungi, bacteria or insects. However, the amount ofresveratrol the fruit or vegetable produces is only sufficient toprotect the individual fruit or vegetable, but it is not nearly enoughto protect an entire batch of wine produced from grapes (about 5 mg/kgin red wine). Moreover, different grape varieties produce differentamounts of resveratrol.

Resveratrol and/or pterostilbene, whether naturally occurring orsynthetic, can be added to wine to act as a preservative. Thesecompounds can be added to wine in amounts ranging from about 5 mg/L toabout 11,500 mg/L, ideally, the compounds should be added twice. It ispreferable to add pterostilbene during the first step of fermentationbecause it is less water soluble than resveratrol and thus will create athin film layer on top of the must, further preventing contact withoxygen and preventing decomposition of the pterostilbene. Resveratrol,which is more stable than pterostilbene, can then be added to finishedwine to act as an antioxidant during aging and storage of the wine.

Resveratrol and pterostilbene also have antibacterial and antifungalactivity in wine. (Biochem. Pharmacol. Jan. 2002 15; 63(2) 99-104).

DETAILED DESCRIPTION OF THE INVENTION

Resveratrol, 3,4′-dihydroxystilbene, also known as 3,4′,5-stilbenetriol,is a phytoalexin produced naturally by several plants when under attackby bacteria or fungi. Resveratrol has also been produced synthetically(see Farina et al., Nat. Prod. Res. 20(3): 247-252, 2006).

Pterostilbene is a stilbenoid compound that is an analogue ofresveratrol. Other names for pterostilbene are4-[(E)-2,(3,5-dimethoxyphenyl)ethenyl]phenol;3′,4′-dimethoxy-4-stilbenol; and3,5-dimethoxy-4′-hydroxy-trans-stilbene.

In grapes, resveratrol is found in the skin and seeds. The amount foundin grape skins varies with the grape cultivar, its geographic origin,and exposure to fungal infection. The amount of time wine spends incontact with grape skins is an important determinant of its resveratrolcontent.

Table 1 illustrates resveratrol content in several types of wines

TABLE 1 Beverage Total Resveratrol, mg/L Muscadine wine 14.1-40   Redwines (Global) 1.98-7.13 Red wines (Spanish)  1.92-12.59 Red grape juice(Spanish)  1.1-8.69 Rose wines (Spanish) 0.43-3.52 Pinot noir 0.40-2.0 White wine (Spanish) 0.05-0.80

As can be seen from Table 1, ordinary non-muscadine red wine containsbetween 0.4 and 12.59 mg/L of resveratrol, depending upon the grapevariety. White wine contains much less resveratrol. This is because redwine is fermented with the skins, allowing the wine to absorb theresveratrol, whereas white wine is fermented after the skins have beenremoved from the grapes. Additionally, red grape skins have moreresveratrol than white grape skins. However, wine grapes that have beensprayed with pesticides that prevent fungal infection contain little, ifany, resveratrol, because there is no need for the grapes to protectthemselves from fungal infection by producing resveratrol. Wine grapesgrown in dry climates have less resveratrol than those grown in humidareas.

It can readily be seen that the amount of resveratrol in wines isextremely low, so that additional resveratrol or pterostilbene must beadded to wines to preserve the wine from oxidation, bacteria and fungi.This is true for red wines, rose wines, and white wines.

Quantitative studies of resveratrol in plants have found that there areonly one to two parts pterostilbene per ten parts of resveratrol. Therelationship between the two compounds and their unequal content inplants is unclear, but it remains the subject of ongoing studies.Dark-skinned grapes are likely to contain the most pterostilbene. Forreasons that are not clear, pterostilbene is normally not found in wine.This may be because it is unstable in light and air, which makes it lesslikely to survive the wine making process.

The following examples are for purposes of illustrating the invention,and are not meant to be limiting in any way.

Example 1

Cabernet Sauvignon and Shiraz were each aged in French barrels (225liter). One barrel of the Cabernet Sauvignon was preserved withresveratrol, and one was preserved with sodium metabisulfite. One barrelof Shiraz was preserved with resveratrol, and the other barrel of Shirazwas preserved with sodium metabisulfite. All of the barrels were agedfor twelve months.

The Cabernet and Shiraz treated with resveratrol had a much more intensecolor than the Cabernet and Shiraz preserved with sodium metabisulfite.

The wines preserved with resveratrol had a fresh and fruity taste. Thewines preserved with metabisulfite had a slight sulfur smell which waseliminated by allowing the wine to breathe for a few minutes prior todrinking.

Example 2

One gram (1000 mg) of resveratrol was dissolved in one liter of 12.5%alcohol non-sulfated Cabernet Sauvignon. While the variety of wine wouldnot make much difference, the alcohol content of the wine might havesome effect on spoilage, as a wine having a higher concentration ofalcohol would need less resveratrol to control spoilage.

The resveratrol enriched wine was stored in an open bottle at roomtemperature. The wine retained its taste and color for more than fivemonths, despite the exposure to atmospheric oxygen and ambient bacteriaand fungi. This is in contrast to similar wines to which sulfite hasbeen added which, once exposed to oxygen, began to deteriorate within afew hours.

Example 3

All the different studies indicated that resveratrol can successfullyreplace SO₂ in the preservation of wine, and that resveratrol is asuperior preservative for wine.

The following parameters were compared: ph, density, Brix and browning(indication of oxidation) in different waves lengths: 280 nm, 420 nm 520nm and 62 nm.

The pH is a measure of the acidity of wine. If wine is too low in acid,it tastes flat and dull. If a wine is too high in acid, it tastes tootart and sour. If the pH of a wine is above about 4.0, the wine becomesunstable with respect to microorganisms; a low pH inhibits growth ofmicroorganisms.

The principal acids found in grapes, and therefore in wine, are tartaricacid, potassium hydrogen tartrate (cream of tartar), malic acid andpotassium hydrogen malate. Tartaric acid and malic acid are produced bythe grapes as they develop. The warmer the climate in which the grapesgrow, the higher is the sugar content and the lower is the acidity.Conversely, grapes grown in a cooler climate have a lower sugar contentand a higher acidity. A winemaker can manipulate the acidity and sugarlevels to produce a wine having the desired characteristics.

Malolactic fermentation is a natural process by which acidity isadjusted. This process lowers the acidity by converting malic acid tolactic acid and carbon dioxide. Nearly all red wines undergo malolacticfermentation.

Brix is a measure of the sugar content of the grape juice at harvest. Atnormal fruit maturity, growth ceases and accumulation of sugar cease atabout 25 Brix. Further increases in sugar content result from water lossas the grape develops into a raisin, which is only desirable in lateharvest wines. The desirable range for table wines is between 19.5 and23.5 in free-run grape juice prior to fermentation.

Density, or specific gravity, of a wine increases as the amount of sugarin the wine increases. The density falls during fermentation as theyeasts convert the sugar to alcohol. Finished wine should have a densityof between about 1.010 and 0.990, for sweet and dry wine, respectively.

Oxidative browning in wine has traditionally been controlled by additionof sulfur dioxide to the wine. Browning is due to oxidation of thepolyphenolic compounds present in wines. In organoleptic terms, thisphenomenon translates into a process of continuous oxidation, a loss ofaromatic freshness, and, in the final stages, in the appearance ofprecipitates of condensed phenolic material in the bottled wine.

Extensive testing was conducted by The Israel Wine Institute on redwines to determine the preservative effects of resveratrol on red wines,particularly in persevering the polyphenols contained in these wines.Two red grapes, cabernet sauvignon and shiraz were used.

The study ran 12 batches for each kind of wine: 3 controls, with noadditives; 3 with 100 ppm SO₂, the accepted industry standard; 3 withlow dose resveratrol, 300 ppm; and 3 with high dose resveratrol, 3000ppm. The resveratrol was added in about 1:1 stoichiometric ratio and 10times the stoichiometric ratio of the sulfite used.

Fermentation was in 225 L barrels. After 12 months of fermentation thewines were tested as described above.

The color of the cabernet sauvignon and shiraz preserved withresveratrol was much more intense for the wines preserved withresveratrol than for the control wines or the wines preserved withsodium metabisulfite.

The wines preserved with resveratrol had a fresh and fruity fragrance,as opposed to a slight sulfuric odor and taste in the wines preservedwith sodium metabisulfite. It is the slight amount of SO₂ present inwines preserved with metabisulfite that makes it desirable to decant thewines prior to serving.

The results of the analytical studies tabulated above show thedifferences in colors among the wines treated with metabisulfite andresveratrol.

In addition to the difference in the wavelength of the absorption ofanthocyanadins and other pigments of the differently preserved wines, itwas also discovered from the absorption spectra that the metabisulfitemetabolites, primarily SO₂, reacted with the polyphenols to form sulfateconjugates by attacking the hydroxyl groups of the polyphenols, whichrenders the anthocyanadins and the proanthocyanadins substantially lessactive antioxidants.

Clearly, the wine preserved with resveratrol is considerably richer innonconjugated antioxidants than wine preserved with metabisulfite. Forthis reason, wines preserved with resveratrol are probably morenutritionally valuable than wines preserved with metabisulfite. Itshould also be noted that resveratrol is a strong antioxidant in its ownright, as well as a known precursor to the important telomerase enzyme.

The amount of pterostilbene added to wine should be about 15% more thanthe amount of resveratrol.

Treatment No. 1 was a control, with no addition of any type ofpreservative.

Treatment No. 2 was a two-stage treatment with metabisulfite, thecurrent standard for preserving wines. Stage 1, the metabisulfite wasadded prior to fermentation at a rate of 50 mg/L. After malic and lacticfermentation 75 mg/L of metabisulfite was added.

Treatment No. 3 was addition of resveratrol. Before fermentation; 180mg/L resveratrol was added prior to putting the wine into barrels forfermentation. After fermentation, 176 g/L resveratrol was added.

Each treatment was repeated five times. The results are shown in Tables2-7.

Tables 8-10 show the results when about 15% “Petit Verdu” was added toimprove the color of wine made from cabernet sauvignon grapes. This is aconventional blend, with the cabernet sauvignon grapes predominating inthe wine.

TABLE 2 Details of Treatment of Variety Cabernet Sauvignon weight ofgrapes Wine Grape (kg) No. Repetition Variety Treat 30 1 I CabernetControl (no 30 2 II Sauvignon additive) 30 3 III 30 4 IV 30 5 V 90 6 IAddition of 90 7 II SO₂ 90 8 III 90 9 IV 90 10 V 90 11 I Addition of 9012 II Resveratrol 90 13 III 90 14 IV 90 15 V

TABLE 3 Details of Treatment of Variety Shiraz weight of grapes WineGrape (kg) No. Repetition Variety Treat 30 1 I Shiraz Control (no 30 2II additive) 30 3 III 30 4 IV 30 5 V 90 6 I Addition of 90 7 II SO₂ 90 8III 90 9 IV 90 10 V 90 11 I Addition of 90 12 II Resveratrol 90 13 III90 14 IV 90 15 V

TABLE 4 Brix Test, Total Acidity (T.A.) pH of Potassium in “new wine”(Thawed Juice) K T.A. (%) Serial (mg/l) pH (g/l) Brix Treat No. 17904.00 3.1 22.8 Control 1 1760 4.09 3.1 21.2 2 1930 4.12 3.1 21.8 3 18204.08 2.9 21.5 4 2050 4.15 3.2 22.5 5 1790 4.00 3.1 22.8 Addition of 61760 4.09 3.1 21.2 SO₂ 7 1930 4.12 3.1 21.8 8 1820 4.08 2.9 21.5 9 20504.15 3.2 22.5 10 1790 4.00 3.1 22.8 Addition of 11 1760 4.09 3.1 21.2Resveratrol 12 1930 4.12 3.1 21.8 13 1820 4.08 2.9 21.5 14 2050 4.15 3.222.5 15We believe that the low acidity value obtained was a result of thetesting on thawed “new wine due to seasons. The HPLC Analysis showedvolumes of 4 g of tartaric acid.

TABLE 5 Analysis during fermentation process were done to test the insugar during fermentation as detailed below 12.10.09 11.10.09 AfterAfter 3 days after Serial decanting pressing 07.10.09 06.10.09fermentation Treat No. 995.2 994.8 Control 1 995.1 995.2 2 995.2 995.31020.4 1040 3.84 3 995.1 994.8 4 994.7 994.9 5 994.6 995.2 1000.4 1006.9Addition of SO₂ 6 995.2 995.3 997.4 1004.4 7 995.2 995.2 1015.1 10343.78 8 995.1 995.3 9 994.6 995.2 10 995.2 Addition of 11 995.6Resveratrol 12 995.2 997.4 1002.9 1016.7 1037 3.81 13 994.6 998.4 1005.414 994.6 998.4 1005.4 15

TABLE 6 Tests of progressing of Malic and Lactic FermentationQualitative Thin Layer Chromatography (TLC) showed completion offermentation. Qualitative results were confirmed by quantitative HPLC.Results of Qualitative Analysis of Malic and Lactic acid in CabernetSauvignon Lactic Acid Malic Acid Treat 1.57 0.05 Control 1.41 0.03Addition of SO₂ 1.47 0.05 Addition of Resveratrol

TABLE 7 Data of Color of Particles (?) of Cabernet Sauvignon Malvidin-3- Average glucoside particle Amount Color Intensity weight Serial(mg/l) 520 420 (g) Sample wine No. 37.4 0.129 0.042 1.22 Control 1 67.10.175 0.060 1.15 2 59.4 0.163 0.054 1.19 3 65.8 0.173 0.056 1.18 4 60.60.165 0.056 1.22 5 37.4 0.129 0.042 1.22 Addition of 6 67.1 0.175 0.0601.15 SO₂ 7 59.4 0.163 0.054 1.19 8 65.8 0.173 0.056 1.18 9 60.6 0.1650.056 1.22 10 37.4 0.129 0.042 1.22 Addition of 11 67.1 0.175 0.060 1.15Resveratrol 12 59.4 0.163 0.054 1.19 13 65.8 0.173 0.056 1.18 14 60.60.165 0.056 1.22 15

“Petit Verdu” was added to improve color of Cabernet wine

“Petit Verdu”

TABLE 8 Brix Test, pH, K, total acidity (T.A.) for “new wine”, PetitVerdu K Brix Serial (mg/l) pH T.A. (g/l) (%) Treat No. 2700 3.86 4.6324.3 Petit 1 2690 3.94 4.73 24.7 Verdu 2

Analysis of Wines

TABLE 9 Results of Testing Cabernet Blend and Alcoholic Fermentation(22.11.09) Total Reducing Phenols Sugars V.A. T.A. Specific Alcohol SO₂FSO₂T (mg/l) (g/l) (g/l) (g/l) pH Gravity (%) (mg/l) (mg/l) Treat 16151.46 0.60 6.32 3.67 995.0 12.8 26.0 75 SO₂ 1938 1.27 0.60 5.95 3.73994.5 12.6 0.0 10 ResveratrolColor Analysis

TABLE 10 Color Analysis of Cabernet Blend Wines (22.11.09) 620 520 420Treat 0.032 0.207 0.159 SO₂ 0.076 0.315 0.217 Resveratrol

Brix Test, pH, K, total acidity (T.A.) for “new wine”

TABLE 11 Brix Test, pH, K, total acidity (T.A.) for “new wine”, Shiraz(08.09.09) T.A. Serial K pH (g/l) (%) Prix Treat No. 2120 3.89 3.77 23.6Control 1 2100 3.81 3.92 23.3 2 2220 3.79 4.65 23.5 3 2240 3.79 4.6123.9 4 2050 3.79 4.85 23.7 5 2120 3.89 3.77 23.6 Addition of 6 2100 3.813.92 23.3 SO₂ 7 2220 3.79 4.65 23.5 8 2240 3.79 4.61 23.9 9 2050 3.794.85 23.7 10 2120 3.89 3.77 23.6 Addition of 11 2100 3.81 3.92 23.3Resveratrol 12 2220 3.79 4.65 23.5 13 2240 3.79 4.61 23.9 14 2050 3.794.85 23.7 15

Analysis of Fermentation Process

TABLE 12 Analysis Tests of Regular Intervals of Density to Test SugarDuring Fermentation as Shown Below Density Density after 1^(st) (???)after decanting pressing pH Treat Serial No. 0.9927 0.9941 3.81 Control1 0.9932 0.9946 3.82 2 0.9932 0.9944 3.91 3 0.9932 0.9952 3.86 4 0.99320.9951 3.98 5 0.9933 0.9954 3.88 Addition of 6 0.9933 0.9954 3.79 SO₂ 70.9933 0.9958 3.95 8 0.9938 0.9952 3.94 9 0.9938 0.9952 3.84 10 0.99370.9946 3.91 Addition of 11 0.9937 0.9945 3.83 Resveratrol 12 0.99320.9943 3.97 13 0.9933 0.9945 3.91 14 0.9932 0.9950 3.85 15

Following Analysis to Test Progress of Fermentation:

Qualitative Thin Layer Chromatography (TLC) that shows completion offermentation confirmed by quantitative HPLC.

TABLE 13 Results of Qualitative Analysis Thin Layer Chromatography (TLC)for (???) of Malic and Lactic Acids 29.09.09 21.09.09 Serial LacticMalic Lactic Malic Treat No. + − Traces + Control 1 + − + + 2 + −Traces + 3 + − Traces + 4 + − Traces + 5 + − Traces + Addition of 6 + −Traces + SO₂ 7 + − Traces + 8 + − Traces + 9 + − Traces + 10 + −Traces + Addition of 11 + − Traces + Resveratrol 12 + − Traces + 13 + −Traces + 14 + − Traces + 15

TABLE 14 Color Data of Shiraz Particles Malvidin-3- glucoside ColorAmount Amount Intensity Serial (mg/g) (mg/l) 520 420 (???) Sample No.5.2 209.7 0.396 0.105 1.10 Control 1 5.9 236.8 0.438 0.115 1.10 2 6.1243.2 0.448 0.125 1.09 3 6.2 247.1 0.454 0.114 1.08 4 5.1 205.2 0.3890.106 1.09 5 5.2 209.7 0.396 0.105 1.10 Addition of 6 5.9 236.8 0.4380.115 1.10 SO₂ 7 6.1 243.2 0.448 0.125 1.09 8 6.2 247.1 0.454 0.114 1.089 5.1 205.2 0.389 0.106 1.09 10 5.2 209.7 0.396 0.105 1.10 Addition of11 5.9 236.8 0.438 0.115 1.10 Resveratrol 12 6.1 243.2 0.448 0.125 1.0913 6.2 247.1 0.454 0.114 1.08 14 5.1 205.2 0.389 0.106 1.09 15

Analysis of Wine

TABLE 15 Results of Analysis of Shiraz Wine Before Adjusting pH TotalReducing Phenols Sugars V.A. T.A. Specific Alcohol SO₂F SO₂T (mg/l)(g/l) (g/l) (g/l) pH Gravity (%) (mg/l) (mg/l) Treat 1600 1.77 0.73 4.784.03 0.9934 14.0 16.0 64 SO₂ 1961 1.81 0.79 4.68 4.04 0.9932 13.9 0.0 3Resveratrol

TABLE 16 Color Analysis of Shiraz (22.11.09) 620 520 420 Treat 0.1680.222 0.168 SO₂ 0.237 0.401 0.237 Resveratrol

It is clear from the above that adding resveratrol preserved theanthocyanadins in red wines, which compounds give red wines theirdistinctive color. These anthocyanadins, as noted above, are preservedbecause of the greater color intensity of the wines preserved withresveratrol. The same results can be expected from the addition ofpterostilbene in about 11.5% of the resveratrol added.

It is clear from the results shown in Tables 2-16 that the resveratrolwas more effective than the control or the metabisulfite in preservingthe colors and thus the polyphenols in red wines.

In addition to preserving the wine, the added resveratrol providesadditional benefits to those consuming the wine. Thus, addingresveratrol to wine enhances the nutritional benefits of wine.

The foregoing description of the specific embodiments will so fullyreveal the general nature of the invention that others can, by applyingcurrent knowledge, readily modify and/or adapt for various applicationssuch specific embodiments without undue experimentation and withoutdeparting from the generic concept and, therefore, such adaptations andmodifications should and are intended to be comprehended within themeaning and range of equivalents of the disclosed embodiments.

What is claimed is:
 1. A method for producing wine that is free of addedsulfite and resistant to oxidation, comprising: a. contacting grape mustprior to fermentation with an agent added for bacteriocidal activity,the agent selected from the group consisting of resveratrol,pterostilbene and mixtures thereof; b. adding a wine producing yeast tothe grape must from step (a); c. fermenting the grape must from step (b)to produce wine, the wine containing a quantity of the agent, whichquantity is enhanced relative to any natural quantity of the agent inthe wine, with the proviso that no sulfites are added at any time duringor after production of the wine, and the agent is present in said winein amounts ranging from about 1 gram/L to about 11.5 grams/L.
 2. Themethod according to claim 1, wherein the agent is present in said winemust in amounts ranging from about 1 gram/L to about 10 grams/L.
 3. Themethod of claim 1, wherein said agent is resveratrol.
 4. The methodaccording to claim 3, wherein the grape must is a must of red grapes,and the wine produced is red wine.
 5. The method according to claim 1,wherein the grape must is a must of red grapes, and the wine produced isred wine.
 6. The method of claim 2, wherein the agent comprisesresveratrol.
 7. The method according to claim 1, wherein the wineproduced is white wine.
 8. The method according to claim 1 whereinadditional agent is added to the grape must during fermentation.
 9. Themethod according to claim 1 wherein additional agent is added to thefinished wine.
 10. The method according to claim 9 wherein additionalagent is added to the wine at the time of bottling the wine.